Air filter



3 Sheets-Sheet l l I I Z0 .7.3/0 J5 Je 95 V. DAHLMAN AIR FILTER Sept. 5, 1933.

/42/5 743522 280g@ zig |652" Z8 Sept. 5, 1933.

v. DAHLMAN 1,925,793

AIR FILTER Filed May 25, 1931 3 Sheets-Sheet 2 V. DAHLMAN Sept. 5, 1933.

AIR FILTER 3 sheets-sheet s Fi'led May 25. 1931 Patented Sept. 5, 1933 C UNITED STATES AIR FILTER Verner Dahiman, New Lenox, lli., assignor to Independent Air Filter Company, Chicago, Ill., a corporation of Illinois Application May 25, 1931. Serial No. 539,852

11 Claims. (Ci. 183-71) The present invention relates to air filters, and has to do particularly with that kind Aof filter in which air is forced or drawn through a dry medium, the major portion of which comprises surfaces substantially parallel to the direction of flow of the air to and from the filter. I

It is an established fact that the filtration o air is highly beneficial. The problem heretofore has been to develop an effective but at the same time an inexpensive filter. To provide a filter with a sheet medium of large area through which the air may pass and yet maintain the filter containing such medium within a small compass has 4been attempted by many but apparently has reached its acme only in the present apparatus.

The objects of the invention include the provision of an unique filter having an extraordinarily large area of exposed filter surface, or capacity, for its cubic content. I

A second .object of the invention is the provision of a new and novel filter structure.

A further object of the invention is an unique means for combining a plurality of spacing elements adapted to be used in an air filter as well as in other devices.

A still further object of the invention is the provision of a new and novel spacer for an airv 'filter or the like.

These objects, and such other objects as may l hereinafter' appear, are obtained by the novel construction, unique arrangement and improved combination of the several elements which constitute the single form of the invention shown in the accompanying drawings, in which: posed upon a frame provided for the ready discharge of used filter material and the reloadin of the unit with fresh material;

Figure 2 is atop view of the filter and frame shown in Figure 1;

Figure 3 is a detail in end elevation showing a filter when its /initial opening operation has been had, Figure 1 heretofore described illustrating in dotted lines the complete open position of suc'h filter;

Figure 4 is a fragmentary transverse section taken on the line 4--4 of Figure 2, looking'in the direction of the arrows;

section taken on the line 5-5 of Figure 2;

Figure 6 is a .transverse section on the line 6--of1i"ig ure'l;l Figure 7 is a detail, in end elevation, partly 5K in section and partly broken away, ShQlYnfthe Figure 1 is a. side elevation of a filter unit dis Figure 5 is a detail in fragmentary longitudinal' -tion of the invention hereinafter given.

Reference should be had first to Figures 1 and 2. These not only illustrate one of the filter units 7o comprising in itself a complete filter, but they also illustrate the manner in which such a unit may be conveniently loaded and unloaded.

For purposes of loading and unloading, there is provided for use with a unit, a frame comprising a pair of horizontal members 10 suitably joined transversely by members 11, the under surfaces of members 11' being in a horizontal plane with the ybottom surfaces of members 10.

Projecting upwardly from said base member 10 80 at the right hand side of Figures 1 and 2 are end standards 12 joined together by a cross member 13 which maintains the standards 12 in spaced relation and also serves as a rest for certain of the filter spacers or lamin.

At the other end of saidV frame, the left hand side'of Figures 1 and 2, is a higher pair of standards 14 which are joined together by a cross mem-l ber 15 like member 13 and serving the same purpose. The member 15 is intermediate the length 90 of standards I4 insteadof the top thereof. The legs. 14 extend to a higher vertical plane and at their tops 4are eut away to provide sockets or bearings 16 for a transverse shaft 17 having an enlarged section 18 upon which a roll of filter 95 material 19 is disposed. The frame just described and illustrated, provides a means for supporting a roll of filter paper, filter cloth or other filter materrial in. strip form permitting of such material comprising longitudinal and transverse wire mem- Aio ' extension portions somewhat removed from their f sides.

bers generally having a greater separation in one direction than in the other and providing a supn1 port for lter material 19 when used within the unit. On top `of screen 25 are strips 26 which may be riveted as Well as sprt welded to members 21. Said strips secure the screen firmly upon the bottom member.

Other strips 27 extend longitudinally of said unit and are joined to members Each cornprises a ibcliaped member with two sections articulated te provide the legs ci the il, the open end receiving the strands oi' screen 25. Each member 27 in addition to being welded to screen 25 is welded or riveted to the members 2i and strips 26. Each. member 2'? may have lugs 28, as previously indicated, to rest on transverse menibers 2G.

At each end of said meinber- Zl., there is disn posed what may be called e, hinge member 33. Said hinge member 33 has an. extension 3d at its top. ln said extension is an aperture into which a connecting means 35 is disposed whereby the connecting means becomes a pivot for a spacer above the base member.' Upon. said base member 2l, two spacer elements are pivcted. Each spacer member has a binge member 36 with two exten sions 37 and 38. The extension 3T is offset to permit of joinder between hinges 3G and 33 with the faces of the extensions therein in contact. The connecting means 35 extend through the peripheries and in juxtaposition with an imagi nary line defining the iimit oi the body of the hinge member.

The body of the hinge member 36 is secured to the side el of the spacer, the upper portion of the hinged member 36 and the upper extension 38 projecting thereabove for reasons shortly to be obvious.

The lower extension 37 andaperture of the body of the hinge member 36 extend below the lowermgcst margin of the spacer member. To an upperextension on a spacer is secured the lower extension of the next spacer thereabove, the 'extension of the lower member projecting upwardly in a straight line, the lower section ci each upper hinge member being made parallel thereto by the osetting of said lower extension.

Similar hinge members and fastening members are at each end of and are yused on each of the intermediate spacer members at their deep The hinge members differ only with respect to those used upon the bottom members 21 and with respect to the top and next to the top spacer members, there being no use for an upper extension upon the topmost spacers, and it is therefore omitted.

Each spacer member comprises a wedge shaped side member 41. Such wedge shaped member is usually or sheet metalv and has a section there of upwardly turned to provide anges 42 and 43. The sides of the spacer converge as its free end is approached.

The material of the iianges t2 vand 43 is adapted to be spot welded or crimped upon an articulated member 44 extending transversely of the device.

At the captive end of each spacer, opposed has plated "se the flanges i2 i3 are connected by an or" member d5 and. do, such members being member Screens 4J? and eil, like screen disposed to rest against the two a-nges and The articulated member fifi is attached to both of screens 4.7 and d8 while the edges of said screens a7 and 48 are covered at the deep end of the spacer member by the members d5 and e6, respectively.

Between the members 45 and d6 there may be spacing wires 49, two or more in number, which extend from `one articulated member i5 to the other articulated member t6.' These wires may be crimped or welded upon said members and 46 just as they are in respect to screen members e? and t8. With respect to the flanges it e3, spot welding is enipioyed to attach the screens thereto. l

The next to the top spacer member is like the Aother spacer members except that it has no top extension. lt may be rounded oft at its top side for convenience.

The top member ci the lter unit comprises angle iron ends 50 and difiere from the lower most member only in that it is attached to one spacer element and in that 'the angle irons are reversed. The lower or base member has spacer members secured at both sides. The top nien?.- ber comprises two angle irons 50 secured to the tcpmost extension of one of the hinges on the second from topniost spacer, there being a screen secured thereon in the saine way as the screens in the base section. At each edge of the screen, the wire ends are covered in the same manner as in the base section to prevent the ends of the wire from projecting.

For holding 'the spacer elements in contact, a fastening means or locking means between the topincst and 'next adjacent spacer -is provided. This may be in the form of a U-shaped clasp 60 pivoted at 61' in the topmost element and having a free end 62 to resliently grip the top surface ci the top member 50. By rotating said member on its pivot 61 the section 62 may be disengaged from the top member 50, permitting of the lift- The next adjacent and topmost spacer element is then lifted upwardly and outwardly in the manner shown'in Figure 3, the movement being in a direction opposite to the movement of top member 50.

The next lower spacer. is then moved outwardly in the same manner as the top member 50. Following this movement, the next spacer element is moved tothe left, in respect to ligure 3. This relation of the spacers, one by one, in clockwise and counterclockwise rotation, is continued until the last is lifted from the/ base, when any lter material 19 in the device maybe removed.

New lter material is inserted upon the screen 25 and stretched thereacrosathe end being positioned so that the proper spacer element above said base may be laid over the lter material 19 recumbent on screen 25. When the spacer element is positioned, lter material is laid upon its upper surface, after which the next spacer element is laid thereover.

Similar manipulations are continued until the lter is completely lled with material 19 when the-required amount o material 19 is cut from the roll thereof. Fastener 60 is then secured in place and the unit is ready for use in the crypt or niche provided therefor.

ing of member 50 in the manner shown in Figure Y are horizontal members 71.

A typical filter installation is illustrated in Figures 6, 7, 8 and 9.

. In the latter two figures, there is shown a frame work of vertical angle irons 70. Therebetween Members 70 and 71 define an area to be traversed by air currents and the position for the filter units for purifying the air in such currents. Other vertical members 72 may be disposed between the members 70. A plurality of rectangular open frames 73 are provided. Members 73 may be bolted to or otherwise secured to members 70 and 72.

Each frame 73 has a triangular member 74 suitably attached thereto. At their rear, members 74 are joinedby a cross member 75. At

the front and top such rectangular frame has a transverse member 76. Suitable packing 77 may be disposed about the opening in frame 73 to engage the filter unit when seated in members 74' to provide an'air-t-ight seal between the frame and filter unit.

Upon each triangular member 74 is a pivoted rod 78. At the end thereof is an L-shaped gripping piece '79 one leg of which is apertured to ride on the threaded rod 78. A wing nut 80 is movable along the threads on rod 78 to draw the gripping piece against a corner of a filter unit to force it into close engagement with the rectangular frame73 and the packing 77 thereon arranged tobe engaged by the unit. The weight of the filter unit is upon the triangular brackets 74. Such unit may be readily attached thereon by the aiixing means just described, and removed with equal facility by releasing the gripping means. A

AThe filter unit is not provided with an enclosing pocket as is quite conventional but is disposed with its six walls generally open. Air of course can only flow through the filter paper, entering at one side and passing out the opposite side. The present arrangement is of few parts,

` is inexpensive to build, is easy to load and unload, simple to maintain, possesses high capacity, and is remarkably efficient. Because of its immense area of exposed filter surface, the velocity of air through the filter may be very low while the capacity is great.

This application covers a device similar to that disclosed in applicants earlier filed application vfor Letters Patent, Serial Number 505,700, en-

movement, relative to said base and also for relative movement between the spacer elements of `each series.

3. A filter unit having a filter medium in strip form arranged in zigzag layers and comprising a base, and spacer elements at opposed sides of said base, the spacer elements at each side comprising a series permanently joined one to another for relative movement, the lowermost spacer being joined to said base.

4. A filter `unit comprising V-shaped spacer elements pivotally connected to one another at their broader ends and interlaced at their narrower ends.

5. A filter -unit comprising series of interlaced V-shaped spacer elements, and connecting means therebetween admitting of angular movement between said spacer elements.

-6. A filter unit comprising series of interlaced V-shaped spacer elements, and connecting 'means therebetween admitting of relative angular movement between said spacer elements and said'connecting means. f

7. A filter unit comprising a base, spacer elements at opposed sides thereof and connected to said base for angular movement, the connecting means between y associated elements providing permanent connection and admitting of angular movement therebetween.

8. A filter unit comprising'a base, spacer ele ments at opposed sides thereof andconnected to said base for angular movement, the spacer elements at each side constituting a series of elements, the connecting means between said as-` sociated spacer elements of a series providing permanent connection and admitting of angular movement therebetween, and locking means for securing opposed spacer elements in an interlaced arrangement with the spacers of one series intermediate the spacer elements of the other 9. A support for a filter comprising uprights to receive one vertical face of said filter, and

` brackets depending from said uprights to engage the bottom thereof, said brackets being at the ends of said llter and leaving said bottom, the top, back, and a large portion of the area of said lends open to the atmosphere.

l0. A' support for a filter unit comprising uprights against which said filter unit is disposed, and triangular brackets extending therefrom a depth equal to the depth of `said unit and to receive the bottom of said unit.

11. Means for supporting an air filter in operable position comprising paired uprights against which said filter is disposed, brackets depending therefrom a distance equal to the depth of said filter and having sections for supporting said filter at the side and outside edges of its bottom,

and means on said brackets engaging said filter to secure it on said supporting sections.

VERNER DAHLMAN. 

